1. Field of the Invention
The present invention relates to methods for analyzing tennis swing and apparatuses used for performing the methods.
2. Description of the Related Art
Swing in tennis is different from player to player. Swing is influenced by the specifications of a tennis racket. For example, when a player attempts to hit a ball with a racket having a low resilience coefficient to obtain a high speed, the player tenses themselves. Meanwhile, when a player attempts to control the speed of a ball in hitting the ball with a racket having an excessively high resilience coefficient, the player loosens their hand. Matching between a player and a racket is important. Appropriate swing analysis allows for accurate fitting. Appropriate swing analysis can contribute to improvement in player's skill.
Swing analysis can also contribute to research and development for tennis rackets. Further, swing analysis can contribute to promotion of rackets.
JP2002-126147 discloses an apparatus in which images of a swing are captured by three high-speed cameras and the behavior of a racket is analyzed on the basis of the obtained images.
JP2006-263340 discloses a swing speed measuring method. In this method, a magnet is attached to the head-side end of a racket. A sensor detects passage of the magnet, whereby a swing speed can be calculated.
JP2009-125499 discloses a method in which a three-axis acceleration sensor and a three-axis gyro sensor are used to analyze a swing.
The measuring apparatus disclosed in JP2002-126147 is large in size and complicated. Such a measuring apparatus is not suitable to fitting in a tennis clubhouse or the like.
In the method disclosed in JP2006-263340, a swing speed can be measured only for a practice swing. By this method, the speed of a swing for hitting a tennis ball cannot be measured.
In the method disclosed in JP2009-125499, it is not clear how each sensor is used.